Alto Metals Ltd (ASX:AME) has struck shallow, high-grade gold during reverse circulation (RC) drilling at and near the Lord Henry pit at Sandstone Gold Project in WA.
The intercepts include 35 metres at 2.2 g/t gold from 43 metres and 24 metres at 2.3 g/t gold from 31 metres.
Lord Henry open pit, part of the Sandstone Project, which ranges across more than 900 square kilometres and takes in the majority of the Sandstone Greenstone Belt, is the gift that keeps giving.
Alto is now in a position to update its mineral resource estimate in the next quarter.
Lord Henry highlights
The assays the company has released today cover 12 RC drill holes over 2,022 metres, drilled to an average depth of 170 metres.
New results south of the open pit include 24 metres at 2.3 g/t gold from 31 metres including 4 metres at 10.9 g/t from 32 metres in hole SRC525 and 15 metres at 1.0 g/t from 63 metres in SCR524.
Alto has also conducted one-metre resplits of previously reported four-metre composites to test extensions of gold mineralisation north of the Lord Henry pit.
These continue to highlight the presence of multiple stacked lodes of high-grade gold, within broader zones of mineralisation.
The results confirm high-grade gold mineralisation and include:
- 35 metres at 2.2 g/t gold from 43 metres, including 2 metres at 24.5 g/t from 73 metres and 1-metre at 14.5 g/t from 87 metres in SRC380;
- 15 metres at 1.7 g/t from 14 metres, including 3 metres at 5.2 g/t from 14 metres in SRC374; and
- 8 metres at 2.7 g/t from 60 metres, including 1-metre at 18.6 g/t from 65 metres in SRC381.
The high-grade gold mineralisation at Lord Henry is contained in multiple stacked lodes that remain open to the north.
Cross-section map of the Lord Henry open pit.
Exploration update
Assays are still pending for more than 50 RC holes, mainly from Lord Henry, Vanguard and Indomitable.
The company is preparing to conduct a gravity survey over the Lords Corridor in early January, to assist in targeting the ‘damage zone’ of the Lords granodiorite along the contact of the ultramafic footwall, at depth.
It also has plans for an induced polarisation (IP) survey over an initial 3 kilometres of the Vanguard trend, to be incorporated into a three-dimensional (3D) inversion model to assist in targeting (3D-IP).
Drilling is scheduled to kick off again in February, with the updated mineral resource estimate on track for delivery shortly after.
Mineral resource estimate
These latest results highlight the significant likelihood of further resource growth, with several previously announced high-grade results outside the current resource.
Work on the updated estimate is progressing well – it’s on track for release by the end of the March quarter 2022, pending further assays.
The current JORC 2012 mineral resource estimate at Sandstone is 6.2 million tonnes at 1.7 g/t gold for 331,000 ounces. These resources are shallow, defined to a depth of less than 200 metres and remain open.
The current mineral resource at Lord Henry is 69,000 ounces of gold (65,000 ounces indicated and 4,000 ounces inferred).